A wavelength tunable filter capable of being driven such that reflecting
mirrors move more distant as well as closer by using the principle that a
direction of the electromagnetic forces changes depending on the
direction of the current flowing perpendicular to the external magnetic
field. According to the wavelength tunable filter of the present
invention, when it is necessary to have the wavelength tuning range and
mechanical structure similar to the conventional wavelength tunable
filter driven in only one direction, it is possible to lower the maximum
force needed to drive the filter to a half, and reduce a probability that
a pull-in phenomenon occurs. On the other hand, it is possible to reduce
a wavelength change time of the element by increasing a resonant
frequency when the same wavelength tuning ranges are implemented by using
the same maximum driving forces.